Hot-air drier.



PATENTED OCT. 11, 1904.

I F. RICHARDS.

HOT AIRDRIER.

APPLICATION FILED mm: 20, 1904.

N0 MODEL.

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I UNITED STATES PATENT OFFICE.

FRED RICHARDS, OF ROCHESTER, P ,HALF TO THE AMERICAN CLAY ENNSYLVANIA, ASSIGNOR OF ONE- VVORKING MACHINERY COMPANY,

OF BUOYRUS, OHIO, A CORPORATION OF OHIO.

HOT-AIR DRIER- SPECIFICATION forming part of Letters Patent No. 772,179, dated October 11, 1904.

Application filed June 20, 1904.. Serial No. 213,290. (No model.)

To a, whom it may concern:

' Be it known that I, FRED RICHARDS, a citizen of Great Britain, residing at Rochester, in the county of Beaver and State of Pennsylvania, have invented new and useful Improvements in Hot-Air Driers, of which the following is a specification. My invention relates to certain new and useful improvements in that class of devices commonly known as hot-air driers employing tunnels through which bricks and other clay products are conveyed and dried by the heat of the tunnels.

Clay-product driers are generally divided into three classes known to the clay-workers art as waste-heat, hot-air, and steam' driers. In the case of waste-heat driers the drier is operated by taking the waste heat from the burning-kilns and transmitting it through the tunnels of the drier, 'VVhen employing hot air as the drying medium, as in the above-named second class, the drier is con: structed with a furnace underneath the track on which the carriers for the waresrun and which furnace transmits the heat to the drying product by radiation through the floor of the tunnel. WVhen steam is used for drying, as in the third-named type of devices, as'eries of pipes is usually assembled at one point or distributed through the tunnels andfthe air' drawn or blown over the pipes, after which the heated air passes through the tunnels, the

steam being circulated throughthe system of pipes.

My present invention is particularly'identified with the devices of the described second class-namely, those using hot air from a furnace and radiated through the floor of the tunnel; and my invention consists of the parts and the constructions and combinations of parts, which Iwill hereinafter describe and claim.

In the accompanying drawings, forming part of this specification, and in which similar letters of reference indicate like parts throughout the several views, Figure 1 is a longitudinal vertical section through one of the tunnels on the line A A of Fig. 2. Fig.

2 isa horizontal sectional View of one tunnel on the line B B of Fig. 1, but showingin plan the track-rails and floors of the remaining tunnels of the series. Fig. 3 is an end view of the drier.

In carrying out my invention I may construct the drier ofany desired length and number of tunnels, and the dimensions can be made to suit the class and character of ware that is to be dried. By way of example, in a drier one hundred (100) feet long the tunnels A, of which four (4:) are shown in the drawings, may be four (4) feet between the walls and live (5) feet six (6) inches high from the paved floor to the under side of the roof. The tunnels are made of the usual or any wellknown material with vertical side and end Walls and roof, and the floor ofeach tunnel is composed for the greater portion of its length of brick laid on cast-iron T-bars P, as shown in Fig. 1, this floor serving also as the top of the flue through which the products of com- .bustion from the furnace or furnaces pass. Along the paved floors of the tunnels A are preferably laid the tracks B, which lead out from the discharge ends of the tunnels and are carried across a firing-pit E by a system of I-beams O built in the walls and serving to support the tracks.

Under the lower or discharge end of the tunnels and located in the firing-pit E, which may be about six (6) feet deep from the floorlevel and extends, say, about fifteen (15) feet beyond the ends of the tunnels and has a width about equal to the width of the combined tunnels of the series, are the furnaces F, which may be of the usual type for burning bituminous coal and have arched roofs a, said roofs being about two (2) feet two (2) inches from the grate-bars to the top of the roof and said furnaces having (4:8) inches long. The furnaces will also be provided with slide or other form of furnacedoors and such other accessories as are usually found in furnaces of the character described, but which are not shown or described in detail herein, as they form no essential part of the present invention.

Immediately over each furnace and next to grate-bars about forty-eightthe brick forming the fire-arch is a cold-air duct G, the dimensions of which may be four (4) inches high and twelve (12) inches wide and which extends back from the face of the furnace, say, about ten-() feet, and on each side of the spring of the fire-arch is a similar cold-air duct H, whose dimensions are about four (4) inches wide and fourteen (14) inches high and which extends back, say, about fifteen (15) feet from the face or front of said furnace. Between the aforesaid coldair ducts is the longitudinally-extending fire-arch or arched fine I, whose length in the size of furnace herein given is about twenty-five feet, and from this point said fine merges into the longitudinally-extending flue J the top of which is formed by the before-described paved floor or partition which separates the fine from the drying-tunnel. The width of the fines I and J is preferably maintained uniform (about twenty-four (24:) inches) from the front, and the combined length of the fines is about fifty feet, from which point the fluepassage is divided by a series of longitudinally-extending partitions L L to form a single central fine M and four side fiues N N, two of which are located upon each side of said central fine. At opposite ends of the partitions L L spaces are left, so that the central flue M will communicate at one end with the side fines N at each side thereof, while at the opposite or front end said fines N will communicate with the other fines N, thereby forminga tortuous passage, in which the prodnets of combustion are retained for the longest possible period, so as to utilize all the heat thereof. The return-fines N N have a length of about forty (40) feet, and they empty back again into a fine at J in Fig. 2, and just beyond which point this flue is provided with a damper or valve Q.

Extending transversely beneath the tunnels is an arched duct R, which leads into the stack S at the bottom and which connects with the damper controlled flue just mentioned and serves to conduct the products of combustion therefrom to the stack. Parallel with the duct R is a cross-duct T, which is preferably located under the entrance end of the tunnels between said end and the duct R and which duct T also extends beneath all of the tunnels of the series and connects with the stack.

' In the floor of each tunnel is formed an opening U, which connects with the duct T, and through these openings the heavier moisture-laden air of the tunnels is drawn by the draft of the stack, and thus carried off. These floor-openings are provided with any wellknown form of sliding dampers, as shown at V.

Over the center of each tunnel, beginning, say, three (3) feet seven (7) inches from the entrance end, an opening is left in the roof, as at W in Fig. 2, and over these holes or openings are erected short wooden or other stacks X, which vary in length as the distance from the stack increases, because of the inclination of the breeching-box Y, with which the stacks X connect.

Each tunnel in actual practice will be provided with such swinging and sliding doors and other accessories as may be required and which are usual in such driers as I have described. These devices, being well known in the art and not being claimed as a part of my invention, are omitted from the drawings.

From the foregoing description it will appear that an essential object of my invention is to obtain the greatest amount of radiatingsurface under the tracks of the tunnel, on which tracks the clay product, loaded on cars, is run into the tunnel and is subjected to the heat radiated from the paved floor thereof. The air-ducts leading from the front of the furnace and extending over and at the sides of the Walls thereof heat the air to a high temperature, which highly-heated air passes up into the tunnels and then through the clay product in process of drying, and which air in process of being heated has a tendency to keep the arches of the furnaces cool, thereby prolonging their life. The hot air through these air-ducts passes up into the tunnels at points where the bricks are partially dried, and in which condition they will stand a high temperature without cracking. The duct T and openings U in the floor of the tunnels afford means of drawing off the moisture-laden atmosphere that hangs along the bottom of the tunnels, while the lighter moisture-laden air is caused to pass through the openings in the roof and into the breeching and stack.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is.-

1. In a drier, the combination with a tunnel through which the wares are passed, of a combustion chamber underlying the discharge end thereof, a main fine below the tunnel and leading from said chamber, a flue arranged substantially in line with the main flue and divided into a narrower central flue and a plurality of narrow fines upon each side thereof, and a flue into which said side fines empty, said central and side fines forming a tortuous passage for the products of combustion, airducts extending over and along the sides of the furnace and delivering into the tunnels, a stack, and a duct connecting therewith and receiving the products of combustion from the fines.

2. In a drier of the character described the combination with a tunnel, of a furnace under the delivery end thereof, a main fine leading from the furnace and extending longitudinally below and substantially parallel with the tunnel, air-ducts along the walls of the furnace and delivering heated air into the tunnel, a flue arranged in line with the main flue and extending longitudinally below and substantially parallel with the tunnel, a flue-composed of a series of parallel longitudinal partitions dividing the flue-space into a narrow central flue and a plurality of narrow flues at each side thereof, a flue into which said side flues empty, said side flues provided with communicating end openings forminga tortuous passage for the products of combustion, a stack, and a duct for conducting the, products of combustion thereto.

3. In a drier of the character described, the combination with a series of parallel tunnels through which the material to be dried is passed said tunnels having floors adapted to radiate heat thereinto, of a furnace under the discharge end of each tunnel, a main flue leading from the furnace-chamber and extending longitudinally below the delivery end-of the tunnel, a flue extending longitudinally below the floor of the tunnel, longitudinally-extending partitions associated with said second flue and dividing the same into a narrower central passage and a plurality of narrow return side flues said central and side flues forming a tortuous passage beneath the floor of the tunnel, a flue into which the said side flues empty, a duct extending transversely beneath the series of tunnels, a stack into which the duct discharges, and air-ducts along the walls of the furnace and delivering heated air into the tunnels.

4. In a drier of the character described, the combination with a series of tunnels having paved floors and tracks along which the wares are conveyed, of a furnace below the delivery end of each tunnel, amain flue or passage below the tunnel and extending the greater portion of the length thereof and receiving the products of combustion from the furnace, longitudinally-extending partitions in said flue between opposite ends thereof and dividing the same into a central flue of reduced width and a plurality of return-flues on each side'thereof whereby a tortuous passage is formed below the tunnel-floor for the products of combustion, a damper-controlled flue into which said side flues empty, a duct extending transversely below the series of tunnels and receiving the products of combustion from the said flues, a stack intowhich the duct delivers, and air-ducts extending along the walls of the furnace-chamber anddelivering heated air into the delivery end of the tunnel.

5. In a drier of the character described the combination of a tunnel and an underlying flue extending substantially the length thereof, said tunnel having a heat-radiating floor separating it from the flue, and said flue divided for a portion of its length into central and return side flues forming a tortuous passage for the products of combustion, a fur-' nace-chamber andfurnace at one end of the flueand a transversely-extending duct into which the opposite end of said flue delivers,

a stack connecting with the duct, air-ducts extending along'the walls of the furnacechamber, and delivering heated air into the tunnels, means for withdrawing heavy moisture-laden air through the lower portion of the tunnel and delivering the same into the stack,

and means for withdrawing the lighter mois-- ture-laden air through the upper portionof the tunnel and delivering said air to the stack.

6. In a drier of the character described the combination of a series of parallel arched tunnels each having an underlying flue extending substantially the length thereof, each of said tunnels having a paved heat-radiating floor composed of bricks and T-barsseparating the tunnel from the flue, an arched furnace-chamber and a furnace under the delivery end of said tunnel and air-ducts along the top and sides of the furnace-chamber and delivering the air heated thereby into the tunnels, a main flue extending longitudinally below the tunnel substantially the entire length thereof and having an intermediate part divided to form a central flue of reducedwidth and parallel return side fines, a flue near the inlet end of the tunnel into which said side flues empty, a damper in said last-named flue, a duct extending transversely beneath the series of flues and a stack into which the duct delivers, a second transverse duct connecting with the stack, said tunnels having floor-openings connecting with the second-named duct whereby heavy moisture-laden air may be withdrawn from the tunnels, and a breeching connecting. with the stack and with openings in the roofs of the tunnels whereby lighter moisture-laden air may be withdrawn from the latter.

7. In a drier of the character described the combination with the tunnels and underlying flues provided with tortuous passages, said tunnels provided with tracks, of a firing-pit below and extending from the delivery ends of the tunnels and a system of I-beams surmounting the pit and supporting the extended portions of the tracks, furnaces under the de-' livery ends of tunnels and connecting with the flu es, the furnace-chambers having arched roofs and'having air-ducts along the top and sides and delivering heated air into the tunnels, a stack, means for delivering the products of combustion from the flues into the stack, and means for separately withdrawing the heavy moisture-laden and light moistureladen air from the tunnels and delivering the same into the stack. a

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

, FRED RICHARDS.

Witnessesz Ron'r. J. CUNNINGHAM, F. B. CHENEY.

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